• 한국자기공명학회논문지
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• 제11권2호
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• pp.73-84
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• 2007

MTH1821 (UniProtKB/TrEMBL ID O27849) is a 96-residue hypothetical protein from the open reading frame of Methanobacterium thermoautotrophicum H one of the target organisms of structural genomics pilot project. Proteins which contain conserved sequence compared with MTH1821 have not been discovered yet and the functional and structural information for MTH1821 is not available. Here, we present the sequence-specific backbone resonance using multidimensional heteronuc1ear NMR spectroscopy and propose the secondary structure using GetSBY software. The backbone resonances of N, HN, $C_{\alpha}$, $C_{\beta}$, CO and $H_{\alpha}$ which are necessary for a prediction of secondary structure by GetSBY were assigned about 98% (557/568). The secondary structure of MTH1821 confirmed that it is comprised of four strand regions and two helical regions. This report will provide a valuable resource for the calculation solution structure of MTH1821 and for the other hypothetical protein that is targeted for structural-based functional discovery.

• Journal of the Korean Wood Science and Technology
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• 제35권6호
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• pp.145-151
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• 2007

산겨릅나무 수피의 성분 연구를 위해 수피를 채취하여 70% 아세톤 용액으로 추출하고 농축한 후 분획깔때기로 헥산, 디클로로메탄, 에틸아세테이트 및 수용성으로 순차 추출하여 동결건조하였다. 에틸아세테이트용성 분획에 대하여 Sephadex LH-20 칼럼크로마토그래피를 반복적으로 수행하여 5개의 페놀성 화합물을 분리하였다. 화합물의 구조는 $^1H-NMR$, $^{13}C-NMR$, 2D-NMR 및 MS 스펙트럼을 분석하여, (+)-catechin (1), (-)-epicatechin (2), (-)-epicatechin-3-O-gallate (3), gallic acid (4) 및 6''-O-galloylsalidroside (5)으로 동정하였다. (-)-epicatechin-3-O-gallate (3), gallic acid (4), 6''-O-galloylsalidroside (5)는 산겨릅나무 수피에서 처음 분리되었다.

• 폴리머
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• 제39권2호
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• pp.287-292
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• 2015

다양한 함량의 테레프탈산, 에틸렌글리콜, 1,4-싸이클로헥산 디메탄올, 이소소바이드로 구성된 일련의 바이오 기반 삼원 공중합체들의 특성을 $^1H$ NMR과 $^{13}C$ NMR을 이용하여 연구하였다. NMR 분석 결과 모두 랜덤한 미세 구조를 가졌고 시퀀스 분포는 이소소바이드의 함량에 따라 영향을 받았다. 시차주사열량계(DSC) 데이터로부터 유리전이온도는 주로 이소소바이드 함량이 증가함에 따라 증가하는 것을 알 수 있었다. 또한 확장된 Fox 식을 이용하여 각 성분의 함량에 따른 삼원공중합체의 유리전이 온도를 예측하고자 하였다.

• 생명과학회지
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• 제17권3호통권83호
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• pp.345-349
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• 2007

PDZ 도메인을 통하여 여러 단백질과 상호작용하며 신경전달 기전에 관여하는 단백질로 Shank1, Shank2, Shank3, PDS-95, AF있다. 본 연구는 Shank3 PDZ 도메인의 구조를 밝히기 위한 첫 단계로서 Shank3 단백질의 PDZ 도메인을 동정하였고, E. coli에서 발현하여 생성된 단백질을 정제한 후 1차 NMR 구조분석을 시도하였다. 그 결과에 의하면 정제된 Shank3 PDZ 단백질은 순도가 높고 안정적인 접힘(folding)구조를 제시하고있다. 현재 완전한 NMR 구조분석을 위해 좀더 많은 양의 정제된 Shank3 PDZ 단백질을 얻고자 연구하고 있다.

• Bulletin of the Korean Chemical Society
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• 제6권5호
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• pp.255-259
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• 1985

The NMR chemical shift arising from 4d electron orbital angular momentum and 4d electron spin dipolar-nuclear Spin angular momentum interactions for a $4d^2$ system in a strong crystal field environment of octahedral symmetry has been investigated when the four fold axis is taken as the quantization axis. The NMR results are comparted with the multipolar shift at various R-values and we find that the exact results are in agreement with the multipolar shift when $R{\geqslant}0.20 nm.$ We also separate the NMR shift into the contribution of the $1/R^5$ and $1/R^7$ terms. It is found that the contribution of the $1/R^5$term to the NMR shift is dominant than the contribution of the $1/R^7$ term. Temperature dependence analysis shows that the $1/T^2$ term is the dominant contribution to the NMR shift for a $4d^2$ system but the contribution of the 1/T term may not negligible. The similar results are obtained for a $4d^1$ system from the temperature dependence analysis.

• 한국자기공명학회논문지
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• 제26권1호
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• pp.1-9
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• 2022

There are two distinct approaches to improving the quality of protein NMR structures during refinement: all-atom force fields and accumulated knowledge-assisted methods that include Rosetta. Mao et al. reported that, for 40 proteins, Rosetta increased the accuracies of their NMR-determined structures with respect to the X-ray crystal structures (Mao et al., J. Am. Chem. Soc. 136, 1893 (2014)). In this study, we calculated 32 structures of those studied by Mao et al. using all-atom force field and implicit solvent model, and we compared the results with those obtained from Rosetta. For a single protein, using only the experimental NOE-derived distances and backbone torsion angle restraints, 20 of the lowest energy structures were extracted as an ensemble from 100 generated structures. Restrained simulated annealing by molecular dynamics simulation searched conformational spaces with a total time step of 1-ns. The use of GPU-accelerated AMBER code allowed the calculations to be completed in hours using a single GPU computer-even for proteins larger than 20 kDa. Remarkably, statistical analyses indicated that the structures determined in this way showed overall higher accuracies to their X-ray structures compared to those refined by Rosetta (p-value < 0.01). Our data demonstrate the capability of sophisticated atomistic force fields in refining NMR structures, particularly when they are coupled with the latest GPU-based calculations. The straightforwardness of the protocol allows its use to be extended to all NMR structures.

• 한국결정성장학회지
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• 제21권1호
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• pp.15-20
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• 2011

[ $^7Li$ ]Magic Angle Spinning(MAS) NMR Spectroscopy를 활용하여 $Li_4P_2O_7$와 $LiFePO_4$ 물질에서 $^7Li$ 핵의 NMR 특성 및 화합물 분자내의 국부적 구조 연구를 수행하였다. $Li_4P_2O_7$와 $LiFePO_4$ 물질 연구는 리튬이온전지에서 고체-전해질 경계상(SEI, solid-electrolyte interphase) 물질 연구를 위한 것이다. $Li_4P_2O_7$와 $LiFePO_4$ 분말은 고상합성법으로 제조하였다.$^7Li$MAS NMR 실험은 $27^{\circ}C$에서 $97^{\circ}C$의 영역에서 변온 실험을 수행하였으며 이는 주변 온도 변화 환경에서 $Li_4P_2O_7$ 물질 내의 Li 핵의 구조 변화를 관찰하기 위한 것이다. $^7Li$ MAS NMR 측정 결과 시료 온도가 $27^{\circ}C$에서 $97^{\circ}C$의 온도 분포 영역에서는 $Li_4P_2O_7$ 물질 내부의 Li 핵은 구조적으로 변화하지 않는 것이 확인되었다. 금번 실험을 통하여 $LiFePO_4$ 분말에 5.0 wt%이내로 포함되어있는 $Li_4P_2O_7$ 물질의 $^7Li$ MAS NMR 신호를 측정할 수 있는 측정 조건을 알았다.

• 한국초전도ㆍ저온공학회논문지
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• 제5권1호
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• pp.1-12
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• 2003

In this paper we present a brief description and summary results of each of our recent activities in three areas, all devoted to NMR and MRI superconducting magnet technologies: 1) development of a high-field LTS / HTS NMR magnet; 2) development of a novel digital flux injector for slightly resistive NMR magnets; and 3) a proposal fer a low-cost MRI magnet system based on $MgB_2$ composite and an innovative cryogenic design / operation concept.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.615-617
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• 2005

[ $^{13}C$ ] NMR spectra were obtained for pure $CH_4$ hydrate in order to identify hydrate structure and cage occupancy of guest molecule. The NMR technique can provide both qualitative and quantitative hydrate characteristics. The moles of methane captured into pure $CH_4$ hydrate per mole of water were found to be similar to the full occupancy value. The overall results drawn from this study can be usefully applied to storage and transportation of natural gas.

• 생약학회지
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• 제18권3호
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• pp.151-167
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• 1987

The $^{13}C-NMR$ chemical shifts of amyrins and their derivatives published up to an early spring of 1987 are listed and a number of methods for signal assignment are explained. A list of 214 amyrins, the $^{13}C-NMR$ chemical shifts of which have been assigned, is included.